Visual tuning indicator



BEST AVNLABLE COPY Jan. 23, 1940. J, UNDSAY 5r AL 2,188,136 VISUALTUNING INDICATOR Filed Feb. 21, 1939 u s Sheets-Sheet 1 l l I I I l I 1l I l l l I I I l 1| IN ENTOR EEST AVAILABLE COPY Jqn. 23, 1940. .1. D.LINDSAY ET AL 2,133,136

VISUAL TUNING INDICATOR Filed Feb. 21, 1939 3 Sheets-Sheet 2 /05" 54 I,/02 l 07 FEST AVAILABLE COPY Jan. 23, 1940. 'J. D. LINDSAY ET 1. ,1

VISUAL TUNING INDICATOR Filed Feb. 21, 1939 3 Sheets'Sheet 3 INVENTOR VPatented 23, 2,188,l36

'BEST AVAILABLE COPY UNITED STATES PATENT OFFICE John D. Lindsay,Wilmette, and Edward J. Wiggins and John A. Press, Chicago, Ill.,assignors to' American Emblem Company, Inc., New Hartford, N. Y., acorporation of New York I Application February 21, 1939, Serial No.257,646

15 Claims. (01. 116-124.1)

The present invention'relatesjo tuning devices adopting a circular drumattached to the axis of for electrical mechanisms and more particularlythe condenser togetherwith pulleys and a piece to dialing -mechanismsand automatic station of, fish line. or other similar substance. Thefish selector devices for radio and television receivers. line afterbeing wound once around the outside Modem radio receiving sets are tunedin on edge of theicircular drum is'then extended to the wave length ofany given broadcasting stathe axis of the tuning knob, is then extendedto tion by varying either the inductance or the a pulley located at thetop of the back of the capacity in the tuning circuits. The majority ofdial, then around this pulley and along the top receiving setsaretunedby varying the capacity of the back of the dial to anotherpulley located of variable condensers in the tuning circuit. at theother end of the top of the back of the i.

In the past calibrated circular dials and codial. a d thence heel; therevolving drum operating ir lar i di t di k ha been d where both ends'of the fishline are attached to' a for tuning purposes. The circulardial system spring which holds the line taut. There is then has Provcnunsatisfactory because of the difattached to that part of the fish lineextendin l5 flculty of precision calibration on the dial, the w n th twpu leys at th t p f t e back of difficulty of accurately reading uch adial a the dial an indicator adapted to move across the well as thedifiiculty of so adjusting the rati face of the dial. .When the tuningknobisrotated ofrotation between the dialing knob and the the fish linethen causes the revolving drum to disc upon which the indicator i tta hd o th t rotate which in turn rotates the condenser and 2o manualprecision tuning may be eflected, at the same time moves the indicatorcorrespond- Consequently manufacturers have n rally b ingly along theface of the dial. The ratio of the gun to discard the circular type oftuning dial rotation of the tuning knob to the condenser and haveadopted in its place th straight li and of the consequent movement ofthe indicator dial, either vertical or horizontal type. In doalo e the da s o e ed by the ratio of the cir- 1mg so, however, they haveencountered many umi nc ef axis of the tuning knob to 25 mechanicaldifflculties and problems which to the circumference of the drum, whichin turn date so far as we are aware have had no effective governs the ln h of e dial i elf. This method and satisfactory solution. Theycommonly now of timing and 0f dialing h pr v n m st unuse what is knownas a straight line type 1 satisfactory inoperation for several reasons:

condenser wherein roughly speaking graph (1) Every set of dialsused bythe manufacturer 80 drawn f th angular han in dir ti f th must becalibrated in advance to meet the deviarevolving portion of the condnser relativ t th tions of the particular type of condenser whichcapacity change should be along a straight line. the manufacturerUnfortunately, however, this does not work out (2) Changes in lengths ofdials requ re a coraccurately in practice. For example, if the firstresponding change in drum diemeters- 35 ten degrees rotation of a givenstraight-line con- The fish line assembly 011 the dialing echdenserrotor gives a change in wave length from ehism must be done y d and q ira-dis- 500 kilocycles to 600 kilocy 1 it may v t proportionate amount oftime and considerable less develop'that the next ten degrees of rotationskill on the Perl; 0f the Workerwill reflect a change of from 600kllocycles to but The line itself 18 Subject o ea a e, 40 690 kilocyclesinstead of to 700 kilocycles. As a deterioration, stretching, slippageand misaligne result, it has been necessary to calibrat th di ment whichrequires replacement and frequent unequally to compensate for thedeviation from dj m which can y be done p p y at a straight line graph.No means so far as w ar the factory or' by a skilled worker. Suddenstrain,

aware have heretofore been found whereby the Particularly so-eelledautomatic tu 45 calibrations on the dial could be made equidissuits instraining or stretching of the fish line tant from each other andsimultaneously comwhich en r q j m n pensate for the straight linedeviation noted. (5) Since use of a fish line requires a rotatingFurthermore, even after overcoming the difelement for operation, it canonly be convenient flculty of proper calibration of the dial, further 1yused w a rotating im Of eendenser- 50 trouble has been encountered inefiecting an ac- It is a principal object of our invention to procuratemeans of moving the indicator along the vide dialing mechanism whicheliminates every dial in precision synchronization with the moveone ofthe objectionable features hereinabove ment of the condenser. The mostcommon dialenumerated in connection with ratio, television ing mechanismheretofore in use has been that or any other electric dialing or tuning.

It is another object of our invention to provide dialing mechanism inwhich no string, no fish line, no belts, no gears, no pulleys and nooperating springs are required. Thus all possibility of slippage, lostmotion, or play is eliminated, thereby assuring accuracy and reducingfriction and wear.

Another object of our invention is to employ a series of leverspositively connecting and coordinating the dialing knob, the condenseror other tuning means, and the indicator each with.

the other. As a result our invention is readily adaptable to any type ofcondenser, transformer or other electrical tuning, means now used orknown. The desired ratio between the rotation of the tuning knob and themaximum degree of rotation of any revolving type of condenser, whateverit may be, is readily maintained and the mechanism may easily be adaptedto any condenser employing a larger or smaller maximum degree ofrotation by simply changing the fulcrum of one lever thereby relativelyincreasing or decreasing the lengths of the arms of another. Themechanism employs no rotating drum and consequently the'length of travelof the indicator itself is not governed or limited by the size of anysuch drum; 'It permits the use of a straight dial, whether vertical orhorizontal, of any desired length; the dial may be calibrated'eitherinto equal or unequal calibrations or segments as may be founddesirable;

, and. both the length of the dial and the system of calibration used iswholly independent of thetype of transformer or, condenser which may beadopted. "Furthermore since there is direct and positive connectionbetween both the tuning knob, the condenser or other tuning means andthe dial indicator itself the possibility of inaccurate dialing due tolost motion, wear, slippage, strain or maladjustment is whollyeliminated and precisiondialing iaassured. This feature of positiveconnection and coordination renders it especially satisfactory anddesirable for automatic dialing as well as manual dialing since itsadjustment cannot be destroyed or varied by the sudden strain whichautomatic tuning involves.

It is another principal object of our invention therefore, to providedialing means which is capable of use advantageously either for manualor automatic dialing and to provide means to permit either said manualor automatic dialing at will.

A further object of our invention is to provide means in ourdialingmechanism which will insure a continuation of precision movementof the dial indicator with relation to the condenser or other tuningmeans regardless of wear or continued usage.

Another principal object of our invention is the provision of means forspeeding up or slowing down the travel of a dial indicator with relationto the travel of a condenser or other tuning unit, and also means ofcoordinating the indicator at any position on a given dial with thetravel of the condenser or other tuning unit along a straight line sothat wherefor example, there is 180 degrees of travel of the condenser'or tuning unit there will be 180 equal or unequal divisions on the dialbut the position of the dial in degrees will always correspond with agiven position of travel of the condenser or other tuning unit. 1

To. the accomplishment of the foregoing and such further objects as mayhereinafterappear, this invention comprises the novelconstruction,

combination and arrangement of parts hereinafter described and thensought to be defined in the appended claims, reference being had to theaccompanying drawings forming part hereof, which show, merely for thepurposes of illustrative disclosure, a preferred embodiment of ourinvention, it being expressly understood, however, that various changesmay be made in practice within the scope of the appended claims withoutdigressing from our inventive idea.

-In the drawings, in which similar reference characters denotecorresponding parts:

Fig. l-is a front elevation of our novel dialing mechanism embodyingboth means for manual and for automatic dialing;

Fig. 2 is a vertical section taken along .line

' 2-2 of Fig. 1 and viewed in the direction ofthe arrows;

Fig. 3 is a rear elevation of the device of Fig. 1;

Fig, 4 is an enlarged sectional detail of the novel coupling means forcoupling or uncoupling the manual tuning knob;

Fig. 5 is a vertical section taken along line 5-5 of Fig. 4 and viewedin the direction of the arrows;

Fig. 6 is an enlarged vertical sectional detail of our novel levermounting means which serves to compensate for wear during use of ourdevice;

Fig. 7 is an enlarged verticalsectional detail of the means for speedingup or slowing down the speed and distance of travel of the dialindicatorzand Fig. 8 is a partial section taken along line' '180"i...e., from a position of said rotor plates giving maximum condenser;capacity to a'position of said rotor plates giving minimum con-.

denser capacity. a

The chassis or frame I 0 comprises two end plates I 0' provided withset-backs. These end plates ID are joined at their set-back verticaledges by a transversely extending horizontal plate l0" and in their rearby a transversely extending, horizontal, vertically slotted plate HP.The end plates III are also suitably joined at their extreme forwardedges by the transversely extending horizontal plate I which has theplurality of perforations I0 in axial alignment with the correspondingslots I0 in the plate It).

Stator frame I! is suitably supported as-at I 5 from the plate l0 andthe rotor shaft I 5 projects forwardly of and above the said plate I0 Alever 20 is adjustably coupled at one end to the rotor shaft I5 by a setscrew 2|. The free end of this lever has attached thereto a laterallyprojecting coupling pin 22 provided with an annular groove 23 for apurpose to be presently described. A T-shaped crank 25 whose cross arm21 is arcuate in shape ispivotally supported in its vertical arm 28 fromthe plate H) as at 29. One of the ends of the cross arm is provided witha laterally extending pin 30 having an annular groove 3|. A connectinglink 34 having enlarged perforations 35 at its opposite ends is looselymounted on the pins 23 and 30 serving to link the lever 28 to the crank26. A coil tension spring 85 attached at its ends in the grooves 23 and8| of pins 22 and 80 serves to urge the pins towards each other in thelink perforations 35. It has sufficient tension to normally maintainthis position of the pins. During tuning of the condenser andparticularly during automatictuning the rotor shaft is subject to suddenchanges in position. If, therefore, the link 34 had no play, as isherein provided, the sudden shift in position would be likely to cause achange of position of the lever 28 relative to the rotor shaft |5notwithstanding the set screw 2|. However, the play permitted by thespring actuated slackly'connected link 8.4 acts as a shock absorberwhich eliminates the. danger of the apparatus going outv of adjustment.

The opposite leg 21' of arm 21 is provided with several perforations 48along the arc of a circle whose center is the axis of pivot point 28. Aconnecting link 42 having a laterally extending pivot pin 48 at one endremovably mountable in one of said perforations 48 serves to connect thecrank 28 with the tuning mechanism now to,- be described.

This tuning mechanism comprises an open frame having front and backplates 58 and 5| respectively. Back plate 5| is suitably spaced from andattached to the front plate 58 by inwardly and laterally extendingflanges 52 and the bolts 52'.

. The open frame is suitably supported from the horizontal plate III ofthe chassis frame by supports 53 attached to plate I8 and to bolts 52.

.Rigidly supported from the inner 'face of the front plate and.extending downwardly therefrom in vertical direction is the manualtuning control support 54. The latter is provided at its upper innerface with an opening 55 into which extends a bearing 55 formed on theplate 58. The rear plate 5| has an opening 51 in axial alignment withthe bearing 58 and a shaft 58 is rotatably borne in the bearing and saidopening extending through plate 5| to its opposite side. Betweenthe'plates 58 and 5| the shaft 58 is enlarged in diameter at 58, formingshoulders 58 near its opposite ends so that it cannot slidelongitudinally in bearing 58 or opening 51. A portion of shaft 58 isprovided'with a key way 58 and an arcuate plate 58 is keyed to saidshaft in the key way and adapted to rotate with said shaft. A cranklever 58 is adjustably attached to shaft 58 by-means of a collar 84attached to the crank lever and by set screw 65. The free end of lever53 is pivotally" but permanently attached to the link 42 in thefollowing manner.

A tapered pin 58 (Fig. 6) corrugated at its narrower end and 58'headed,at its broader end 88 is inserted through a tapered opening 51 inthe lever 83. Then a spring washer 88 is mounted on the pin over itsnarrower end and thereafter the said narrower end is driven into andriveted in the opening 42' in the link 42. The spring washer is normallypartially compressed and tends to urge the lever 63 toward the thickerend of said pin 55. Thus as the pin 88 and the material about theopening 61 wear during use, the lever is moved by the spring washer ontoa thicker portion of the pin, which thus serves to take up play" lationto the. condenser or other tuning means regardless of wear induced bycontinued, frequent usage.

The dial used with my device comprises a dial plate 18 suitablysupported from the front face of the frame plate 50. The dial plate maybe calibrated into suitable graduations or divisions 1| over thefrequency range or ranges in which the radio set is designed to operate.A carriage 12 slidably mounted on a slide bar 13 suitably car- I 88 withthe same type of tapered pins and spring washer connection heretoforedescribed and illustrated in detail in Fig. 6. The opposite end of linkis similarly pivotally connected at 88 to one arm 8| of a lever 8|..Lever 8| intermediate its ends. has a laterally extending bearing block88 (see Fig. 7). This bearing block which is fixed to said lever 8| hasa bore 88 enlarged at its forward end 83. A pin 84 having a tapered head88 is adapted to be inserted through the bore 83' from the opposite faceof plate 5| through a cam groove to be presently described, and held inposition in the bore 88' by a removable collar 88 at the inner end ofsaid pin, a compression spring 81 being mounted around said pinbetweensaid collar and the inner end 83 of said block 83. In this mannera tight slidable engagement of the head 84' of the pin in groove 85under the action of .spring 8'! always is insured notwithstanding wearof the edges of the groove 85 or the pin head 84' during long continuedusage. If desired a straight pin fixedly mounted in the block 83 andextending into and operating in cam groove 85 with close tolerance canbe substituted for pin 84. However the wear compensating pin 84 ispreferable.

, The opposite arm 8| of the lever 8| is piv- V otally connected at, Mto one end of the crank lever 88 whose other end is keyed at 98' to therotatable shaft 80 rotatably borne in the bearing 8| extending from theinner face of plate 58 .and the axially aligned perforation 92 in theplate 5|. The pivotal connection 8| is the same type of wearcompensating connection hereto-- fore described and illustrated in Fig.6..

A connecting link 95 is pivotally attached at, one end 95' to a pointintermediate the ends-of lever 88 with the same type of wearcompensating connection. The opposite end of the link 85 is similarlyconnected at its other end 95 to the driving plate 8|! in such a waythat through the levers and groove and linkages rotation of the arcuateplate '68 in one direction will cause transverse movement of the slideand indicator across the graduations on the dial plate .18 in the samedirection as the rotor plates M are thrned. As viewed from the directionof Fig. 3, clockwise rotation of the driving plate 68 will causeclockwise rotation of 'the rotor plates I4 and simultaneous movement ofthe carriage l2 and indicator 14 from left to right through the variouslevers and linkages hereinbefore described, and movethe carriage l2 andindicator 14 in opposite direction from right to left when the arcuatedrive plate 60 is rotated counterclockwise.

The movement of the indicator I4 is synchronized to the condenser rotormovement more particularly by the shape of the groove or guide in whichthe pin 84 travels. This groove or guide 05 is so constructed that theposition of the indicator 14 is at all times in a direct degree relationto the position of. the condenser rotor or other tuning unit. Both thelength and rate of travel of the indicator I4 along the dial isdetermined by the length and direction of the groove or guide, 05 inwhich the said pin or lug 84 travels. -The curve of the groove or guidecan be changed to give' closer or wider spacing in any part of thetravel course of the indicator. By this means, not only is any variationin the straight line graph'of the condenser or other tuning unitcompensated for so that the dial itself -may be marked off in uniformlyequal calibrations, but also, if it is desired, where many stations comeinclose together, that the spacing on the dial be lengthened in thisarea, it can be done by changing the curve of said groove or guide. Whenwe speak of groove or guide, its equivalents, viz., track, slot, cam orthe like are contemplated.

I in diameter at I05 and extends into a recess I00 in the knob I00. Theopposite end of the bushing is provided with two diametrically spacedballs I01 or the like suitably fixed in the bushing and which projectinto the space I00 between the rear face of the ring I 05 and thesupport 54.

Two arcuate cam members IIO are mounted on' the support 54 atdiametrically opposite points about the shaft I02. These members haveraised cam portions 0' extending into the space I 00 and toward the ringI05. Each raised portion is provided with a depression or notch III toreceive one of the balls I 01 for a purpose to be presently described.

The forward end of shaft I02 is reduced in diameter at I02 and has keyedthereon a clutch ring III whose rear face H3 is conical. The shaft I02also extends slidably and rotatably through a second clutch ring II4whose front face 4' is coned in opposite direction to face II2. Acompression spring H5 is mounted around the shaft I02 in a recess II4behind theface 4' of the second clutch ring and a retaining collar H0 ismounted on the shaft end and held in place, for example, by turning orflaring over the inner shaft end at I02 Clutch ring II 4 is carried inaxial alignment with opening 54 and spaced therefrom by a bracket II1suitably can-led from the support 54.

BEST AVAILABLE COPY rotated upon rotation of the dial knob I00, there issufficient friction between the face H0 and said edge to cause thelatter to be moved with corresponding rotation of the arcuate plate ordisk 00. As a result the condenser rotor I4 and the indicator I4 arealso moved through the agency of the levers and links hereinbeforedescribed. Rotation of the clamping ring I05 so that the balls I01 rideup and are caught in the with the arcuate disk 60 is efiected simply byrotatingthe release ring I05 so that the balls ride of! the raisedportions 0' of the cams H0.

The structure hereinbefore described permits ready attachment ofautomatic tuning means. To this end, a concave member I20 extendingtransversely between the end plates I0' of the chassis or frame I0 isprovided. This concave member has oppositely-extending flanges I2I in asubstantially diametrical plane which serve as cam surfaces in a mannerto be presently described. One end of the concave member is providedwith an end-plate I20 which is pivoted to one end plate I0. Suitablyfixed to the other end of the member I20 and extending in a plane normalto the flanges I2I is a lever I23. This lever is fulcrumed at I23 to theother end plate I0, the fulcrum serving as the center of rotation of theconcave member I20. This lever I23 is also connected by a universaljoint connection at I24 to a link member I25 whose opposite end isattached to the cross arm 21' of the T shaped member 26 by a universaljoint at I26. In this manner rotation of the concave member I20 willcause corresponding rotation of the rotor plates I 4 through the agencyof the lever I23, connecting link I25, a shaped member 26, link 34 andlever 20. Simultaneously rotation of concave member I20 will causecorresponding movement of the indicator 14 through the agency of leverI23, connecting link I25, T shaped member 26, link 42, lever 63, arcuatedisk '60 link 95, lever 88, link BI; groove 05, link 80 and slide 12.The degree of angular rotation of the concave member I 20 is soadmeasured as to be sufficient to eifect rotation of the rotor platesI4, through the linkages and levers hereinbefore described.

Automatic means for rotating the member I20 through any desired numberof degrees intermediate its limiting positions is provided. This meanscomprises a plurality of plunger members I29 guided in the perforationsI0 of the horizontal plate I0 and the slots I0 in the horizontal rearplate I0 of the chassis I0, andextending through vertical slots in theconcave member I20. Each plunger member comprises a U shaped frame I00whose side legs III extend parallel to each other to define a space ISIand are then bent inwardlytoward each other at I30 and, then extendparallel to each other at I30 to define a second smaller space I 02. Oneof the legs of said frame at I30 is longer than the other leg andprojects through a vertical slot in the concave member I20 and avertical slot I0 in the plate I0 Pivotally supported at I from the legportions I30 in the space I32 is a semi-circular disc I36. This disc isprovided with suitable laterally projecting stops I3! which areengageable with the leg portions I 30 and serve to limit rotation of thedisc to a desired number of angular degrees. In the embodiment shown,the limits of rotation are substantially 60 degrees apart. This disc isadapted to be locked in any adjusted position between its limits ofrotation by a locking member I38 slidably movable toward and away fromthe circumferential edge of the disc I36. The member I30 in theembodiment shown has the forwardly projecting noses I39 which areadapted to frictionally engage the said disc edge and lock the discagainst rotation when pressed thereagainst. At its rear the lockingmember has a transversely extending guide plate I40 slidably movable inthe space I3 I. The locking member is adapted to be tightened againstthe disc by the bolt I4I threaded in a nut carried in the frame I30 atI30 The forward end I4I' of the bolt extends through an opening I40 inthe guide plate I40 and bears against the rear edge I38 of the lockingmember so that when the bolt is screwed inwardly, it forces the lockingmember against said circumferential edge of said disc I36 to lock thelatter in its adjusted angular position. A suitable finger knob I43 iscarried on the forward end of the bolt. The entire plunger I29 isreciprocally slidable transversely of the plates I0 and I 0 Tensionspring I45 suitably attached at its ends to the plate I0 and to theframe I30 serves continuously to urge the plunger outwardly so that itsguide plate I40 abuts the inner face of the plate I0 Pressure of theplunger inwardly against the action of the spring causes the diametricaledges I36 of the semicircular disk to engage one or the other of theflanges I2I of the concave member I20 and to rotate the latter into suchposition that both flanges are in directional alignment with the saiddiametrical edges I36. The rotation of member I20 causes the rotor platerotation and indicator movement as hereinbefore described through thelevers and links. A change in angular adjustment of the disk I36 resultsin a change of angu lar position of its diametrical edges I 36'. As aresult a corresponding change in the ultimate angular position of theconcave member I20 also is effected when the plunger is moved inwardly.

A plurality of identically constructed plungers I29 are provided, sixI29A-I29F being shown in the present embodiment. The corresponding discI36 of each may be adjusted to a different angular position. As a resulteach plunger will always rotate the concave member I20 to an angularposition corresponding to the setting of its individual disc I36. Thesprings I45 normally retract the plungers I29 so that then discs I36 areentirely clear of the concave member I20. Thus when an individualplunger I29 is pressed in wardly only its disk I36 acts upon the concavemember I20 without interference from the other discs. At the completionof the particular plunger stroke, and during which the concave memberhas been given a definite angular rotation by the particular disk I 36,the plunger is retracted by its spring I45, its disk I36 moving awayfrom the said concave member which, however, remains in its angularlyadjusted position.

In this way, any one of the plungers upon being moved inwardly willalways cause a rota- ZEST AVAIL/Wu: LUll tion of the concave member I20either clockwise or counterclockwise depending upon its position, tobring it into a position corresponding to that of the particular diskI36 on the particular plunger moved inwardly. For example, if plungerI29B has its disk I36 so adjusted as to rotate the concave member I20 toan angle of 15 with the vertical, plunger 129C has its disk I36 soadjusted as to rotate the concave member I20 to an angle of 45 with thevertical and plunger I29F has its disk I36 so adjusted as to rotate theconcave member I20 to an angle of 30 with the vertical, pressureinwardly of plunger I29B will give the desired 15 inward rotation to themember I20. Thereafter pressure inwardly of plunger I29C will give themember I20 an additional rotation of 10 so that the net rotation of thelatter would be 25 from its starting position. Likewise pressureinwardly of plunger I29F would now rotate the member I20 an additional 5so that its net movement from its starting position would be 30.Pressure now of plunger I29B would cause the concave member to berotated in opposite direction over an angle of 15 so that its finalposition would be at a position 15 with the vertical starting position.In other words pressure inwardly of any one of the plungers I29A-I29Fwill always rotate the disk I20 to the angular position with thevertical defined by the diametrical edges I36 of its particularsemicircular disk I36.

Coordination between the manual tuning and automatic tuning means iseifected as follows:

The releasing ring I05 is so rotated as to permit frictional engagementof the arcuate plate between the clutch rings I I3 and H4 at which timemanipulation of the tuning knob I00 will cause corresponding movement ofboth the rotor plates I4 and the indicator 14 through the agencies ofthe levers and links hereinbefore described. The set is then tuned bythe movement of the knob I00 to a particular station. When a particularstation hasbeen tuned, the release ring I05 is rotated to automatictuning position, i. e.

, to disengage the arcuate plate 60 from between the clutch rings II3 toH4. Then the bolt I4I of one of the plungers I29 is loosed and thelatter is pressed inwardly. Since itssemicircular disk I36 is now loose,its diametrical edges I36 adjust themselves to the angular position ofthe flanges I2I of the concave member I20. The bolt I 4I is thentightened, setting the said disc in said angular position. Thereafterinward pressure on this particular plunger I29 will always rotate theconcave member I20 to the particular angular position of the flanges I2Iwhich mate with the said angular adjusted position f the particular discI36. Successive plungers may be similarly adjusted for other dialsettings at particular stations.

Since all the plungers I 29 are free and clear of the concave member I20except when pressed inwardly, the aforementioned adjustment of thesemi-circular discs I36 does not interfere with manual tuning which isdone by the rotation of tuning knob I00 while the release ring I06is insuch position as to permit frictional engagement of the clutch rings H3and I I4 with the drive disc 60. During automatic tuning, the releasering I05 is rotated to cause the clutch rings H3 and I I4 to separateand free the disc 60. Operation of any plunger during this releaseposition will tune the set to the station for which the particularplunger has been adjusted. Since the individual semicircular discs I36are readily adjustable, any plunger may be changed to tune the set toany desired radio station by the owner of the set without requiring anyalteration other than a change in position of its semi-circular discI36. Such adaptability vastly increases the automatic tuning range whichin most commercial devices has heretofore been limited to a few standardbroadcasting stations.

It is understood, of course, that the proportioning of parts and degreesof rotation and movements of various of the discs, levers and links canbe anything practically desirable. In the particular embodiment hereinshown, the condenser rotor plates are rotatable over 180 degrees. Theindicator I4 is adapted to move over a dial face a longitudinal distancecorresponding to the 180 degrees angu ar rotation of said rotor plates.In effecting the movement, the levers and links are so proportioned thata rotation of 45 angular degrees of the arcuate disc 60 will impart arotation of 60 angular degrees to the T- shaped arm 21. The latter inturn through the link 34 and crank lever will rotate the condenser shaftI5 through 180 degrees. Likewise the 45-degree rotation of arcuate disk60, through the link 95, lever 88, link 8|, groove 85, pin 84, link 8|and carriage I2 will simultaneously move the indicator 14 over the full180-degree length of the dial face. Furthermore, the concave member I20,which is connected to the T-shaped arm 21 through link I25, is alsorotatable over a 60- degree span and full rotation within the span. ofthis member I25 will eifect the 180-degree rotation of the rotor shaftand 180-degree movement of the indicator.

A change of position of the fulcrum 43 of the link 42 by shifting it toone of the other holes in the arm 21' will reduce or enlarge the rangeof travel of the indicator I4 without requiring any change in the otherparts.

The radius of the edge of the slot 60' is so admeasured that a rotationof approximately 1350 degrees of the tuning knob I 00 is required toproduce 180-degree rotation of the rotor shaft I5.

It is understood, of course, that the relative angular movements hereinnoted are simply by way of example. Alterations in angular movements toadapt the apparatus for tuning devices having more or fewer angulardegrees of rotation are contemplated and within the scope of ourinvention.

It is also to be understood that various changes in structural detailsare fully contemplated as part of our invention within the scope of theappended claims. We do not therefore wish to be limited to the exactdetails shown and described.

We claim:

1. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansconnecting said member to said tuning unit, an indicator, a dial overwhich said indicator is mov able, linkage means connecting said memberand said indicator for simultaneous movement of the latter insynchronism with the movement of said tuning unit, means for moving saiddriving member, and means associated with said second named linkagemeans for variably regulating the speed of travel of said indicatorrelative to the movement of said tuning unit.

2. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansconnecting said member to said tuning unit, an indicator, a dial overwhich said indicator is movable, linkage means connecting said memberand said indicator for simultaneous movement of the latter insynchronism with the movement of said tuning unit, manual means formoving said driving member, and means associated with said second namedlinkage means for variably regulating the speed of travel of saidindicator relative to the movement of said tuning unit.

3. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansconnecting said member to said tuning unit, an indicator, a dial overwhich said indicator is movable, linkage means connecting said memberand said indicator for simultaneous movement of the latter insynchronism with the movement of said tuning unit, means for moving saiddriving member to a predetermined position, and means associated withsaid second named linkage means for variably regulating the speed oftravel of said indicator relative to the movement of said tuning unit.

4. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansconnecting said member to said tuning unit, an indicator, a dial overwhich said indicator is movable, linkage means connecting said memberand said indicator for simultaneous movement of the latter insynchronism with the movement of said tuning unit, manual means formoving said driving member, means for moving said driving member to apedetermined position, means for coupling one of said two driving meansat a time to said driving member, and means associated with said secondnamed linkage means for variably regulating the speed of travel of saidindicator relative to the movement of said tuning unit.

5. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, connectingmeans for coupling said member to said tuning unit, means for indicatingthe relative position of said tuning unit, connecting means for couplingsaid indicating means to said driving member to produce simultaneousmovement of said indicating means and said tuning unit, means for movingsaid driving member, and wear-compensating means between each of saidconnecting means and said driving member.

6. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansfor coupling said member to said tuning unit, means for indicating therelative position of said tuning unit, linkage means for couplingsaid,indicating means to said driving member to produce simultaneousmovement of said indicating means and said tuning unit, and means formoving said driving member.

7. In electrical apparatus having a movable tuning unit, a drivingmember for moving said tuning unit, connecting means for coupling saidmember to said tuning unit, means for indicating the relative positionof said tuning unit, connecting means for coupling said indicating meansto said driving member to produce simultaneous movement of saidindicating means and said tuning unit, and means for moving said drivingmember. wear-compensating means between each of said connecting meansand said driving member, said wear-compensating means each including atapered pivot pin and a spring means about said pin at all pivot pinjunctions between each BEST AVAILABLE COPY gf said connecting means andsaid driving mem- 8. In electrical apparatus comprising a movable tuningunit, in combination, a driving member for moving said tuning unit,connecting means for coupling said member to said tuning unit, means forindicating the relative position of said tuning unit, connecting meansfor coupling said indicating means to said driving member to producesimultaneous movement of said indicating means and said tuning unit,means for moving said driving member, each of saidconnecting meansincluding a plurality of levers and links, and wear-compensating meansfor pivotally joining the respective links and levers together.

9. In electrical apparatus having a 'movable tuning unit, a drivingmember for moving said tuning unit, connecting means for coupling saidmember to said tuning unit, means for indicating the relative positionof said tuning unit, connecting means for coupling said indicatin' meansto said driving member to produce s ultaneous movement of saidindicating means and said tuning unit, and means for moving said drivingmember, each of said connecting means including a plurality of leversand links, wear-compensating meansfor pivotally joining the respectivelinks and levers together, said wear-compensating means each including atapered pivot pin and spring means about said pin at all pivot junctionsbetween the said links and levers.

10. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, linkage meansfor coupling said member to said tuning unit, means for indicating therelative position of said tuning unit, linkage means for coupling saidindicating means to said driving member to produce simultaneous movementof said indicating means and said tuning unit, means for moving saiddriving member, means associated with said last-named linkage means forvariably regulating the speed of movement of said indicator meansrelative to the movement of said tunin unit, and means forsimultaneously changing the ratio of the movement between said lastnamedmeans and the movements of said tunin unit and said indicating means.

11. In electrical apparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, connectingmeans for coupling said'member to said tuning unit, means for indicatingthe relative position of said tuning unit, connecting means for couplingsaid indicating means to said driving member, manual means for movingsaid driving mem-' ber, clutch means for coupling said manual meansmeans to said driving member for manual operation, and release meansoperating on said clutch means for uncoupling the said manual means fromsaid driving member, and means operable while said manual means isuncoupled for moving said driving member to a predetermined setting.

12. In a device as per claim 11, in which said means operable when saidmanual means is uncoupled comprises a rotatable member, linkage meansconnecting said rotatable member with said driving member, and a plungeroperated cam for rotating said rotatable member over a predeterminedangle of rotation.

.13. In a device as per claim 11 in which said means operable when saidmanual means'is uncoupled comprises a rotatable member coupled to saiddriving member, and an adjustable cam adapted to engage with saidrotatable member and rotate the latter over a predetermined angle ofrotation. Y

14. In a device as per claim 11 in which said means operable when saidmanual means is uncoupled comprises a rotatable member coupled to saiddriving member and a plurality of plunger-operated cams, each adapted torotate said rotatable member overa predetermined adjustable angle ofrotation.

15. In electricalapparatus comprising a movable tuning unit, incombination, a driving member for moving said tuning unit, connectingmeans for coupling said member to said tuning unit, means for indicatingthe relative position of said tuning unit, connecting means for couplingsaid indicating means to said driving member to produce simultaneousmovement of said indicating means and said tuning unit, means for movingsaid driving member, and means associated with said second namedconnecting means for variably regulating the speed and distance ofmovement of said indicator means relative to the movement of said tuningunit.

JOHN D. LINDSAY. EDWARD J. WIGGINS. JOHN A. PRESS.

D l S C L A I M E R 2,188,136.John D. Lindsay, Wilmette, and Edward J.Wiggins and John A. Press, Patent dated J anu 23, 1940.

Chlcago, I11. VISUAL TUNING INDICATOR. Disclaimer filed October 20,1942, by the assignee, American Em lem Company, Inc. Hereby enters thisdisclaimer to claims 11 and 14 of said Letters Patent.

[Ofiic'ial Gazette November 24, 1942.]

DISCLAIMER 2,188,136.J0hn D. Lindsay, Wilmette, and Edward J. Wigginsand John A. Press, Chicago, Ill. VISUAL TUNING INDICATOR. Patent datedJanu 23, 1940. Disclaimer filed October 20, 1942, by the assignee,American Em lem Company, Inc. Hereby enters this disclaimer to claims 11and 14 of said Letters Patent.

[Ojficial Gazette November 24, 19142.]

DISCLAIMER 2,188,136.-Jolm D. Lindsay, Wilmette, and Edward J. Wigginsand John A. Press, Chicago, Ill. VISUAL TUNING INDICATOR. Patent datedJanu 23, 1940. Disclaimer filed October 20, 1942, by the assignee,American Em lam Company, Inc. Hereby enters this disclaimer to claims 11and 14 of said Letters Patent.

[Ojficial Gazette November 24, 1.942.] V

